Fix most of the error while running the specs.

This will be an the update to 1.0.0 since it add breaking change to the gem configuration process.

## New Features
### The user can now pass configuration arguments following this scheme:

```ruby
Leetchi.configure do |c|
    c.preproduction = true
    c.partner_id = 'example'
    c.key_path = './spec/support-files/example.pem'
    c.key_password = ''
end
```

The **preproduction** attribute let you specify if you want to use the preproduction api endpoint.

The **partner_id** is the id that was issue to you during you registration process.

The **key_path** and **key_password** arguments are here to let you use the key you've created before the registration process.

This configure method can of course be use to define a Ruby on Rails initialiser.

### Add a default configuration to be used in preproduction environment to run the test in CI